Brace-head for boring-tools.



No. 656.069. Patented Aug. 14, I900. A. WE|SENHOBN..

BRAOE HE'AD FOR BORING TOOLS.

(Application filed Mar. 19, 1900.)

(No Medial.)

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QN/ITED TATES AUGUST WEISENHORN, OF HELENA, MONTANA, ASSIGNOR OF ONE-THIRD TO WILLIAM WEISENHORN, OF QUINCY, ILLINOIS.

BRACE-HEAD FOR BORING-TOOLS.

SPECIFICATION forming part of Letters Patent No. 656,069, dated August 14, 1900.

Application filed March 19, 1900. Serial No. 9,317. (No model.)

To all whom it may concern.-

Be it known that 1, Answer WEISENHORN, a citizen of the 7 United States, residing at Helena, in the county of Lewis and Clarke and State of Montana, have invented new and useful Improvements in Brace-Heads for Boring- Tools, of which the following is a specification.

This invention relates to an improved bracehead for boring-tools and like implements, and has for its object to provide a simple, easily-adj usted, and reliable means for firmly holding a bit in its socket in such manner that it will not become detached or loosened while the tool is in operation and so that the bit can be pulled out from the work without turning backward, thereby saving time and also clearing the hole of all chips thatwould otherwise remain there and obstruct the same.

My improved brace-head comprises, essentially,but three pieces,each of simple construction-namely, an externallyscrew-threaded socket-piece having its periphery provided with longitudinally-extended grooves, an internally-screw-threaded sleeve or shell to engage and surround the said socket-piece, and spring clamping links held between said socket-piece and shell, with the link arms or shanks engaged in the longitudinal grooves of the socket-piece and with the outer looped portions of said links crossing each other in such manner as to be capable of securely embracing the inserted bit at the outer side of a shoulder thereon, whereby on screwing down the outside shell the crossed links will be made to clasp the bit so firmly that it cannot become detaohed'from the socket-piece nor loosened therein until the sleeve or shell has been unscrewed, the compressed spring-links meanwhile exerting a locking-pressure within said shell that will effectually prevent it from working loose of its own accord, and thus the bit cannot loosen, for the brace being turned to the right while in operation and the outside shell turning down in the same way it is obvious that it will tighten more and more while the tool is in use.

My inventioncons'ists in a bracehead comprising an externally-screw-threaded and longitudinally-grooved socket-piece, an internally-screw-threaded shell, and crossed springlinks compressible between said socket-piece and shell and having their outer crossed portions adapted to securely clasp a bit adjacent to a shoulder thereon, whereby the bit is held firmly in its socket.

The invention further consists in features of construction and combinations of parts in a brace-head, as hereinafter more particularly set forth.

In the annexed drawings, illustrating the invention, Figure 1 is a part longitudinal section of my improved brace-head, showing the simple manner of securing a bit firmly therein. Fig. 2 is a similar view with the socket-piece and spring-links shown at a right angle to the preceding view. Fig. 3 is a transverse section through the bit-socket. Fig. 4 is a perspective of one form of the crossed springlinks. Fig. 5 is a similar view of another form of crossed spring-links.

The reference-numeral l in Figs. 1 and 2 designates a bit having a shoulder 2 on its shank portion 3, which may be somewhat tapered, as usual. This bit-shank 3 may be square or polygonal in cross-section. To re ceive the bit-shank 3, there is provided a socket 4, Fig. 3, which is formed in the outer end portion of a socket-piece 5, Figs. 1, 2, and 3, that constitutes the central or main portion of my improvedbrace-head. The socket 4 is square or of other polygonal form to correspond with the polygonal shape of the bitshank. The shank portion 6 of this socketpiece 5 may be integral with the brace or it may be secured thereto in any suitable manner. On its outside the main portion of the socket-piece 5 is provided with screw-threads to be engaged with the internal screw-threads of an outside sleeve or shell 7, as shown in Figs. 1, 2, and 3. The outer end portion of the externally-screw-threaded socket-piece 5 is preferably somewhat tapered, as shown in Fig. 1.

In the screw-threaded outer surface of the socket-piece 5 there are formed on each side two parallel longitudinally-extended grooves 8, which receive the shank portions or springarms 9 of the crossed links 10, that are arranged between the socket-piece 5 and out- 10o side shell? to serve as a compressible clamping means for holding the bit 1 firmly in its socket, so that it cannot possibly become detached or loosened when the shell 7 is screwed properly into place on the inside socket-piece. Between the two grooves 8 in each side of the externally-screw-threaded socket-piece 5 there is a rib or wall 11, Figs. 2 and 3, that is tapered OK at its outer end to correspond with the taper given to the two longitudinally-grooved sides of said socketpiece. This rib or wall 11 separates the parallel grooves 8, and the tapering of the socketpiece at the outer end portions of said grooves and rib permits the spring-arms 9 of the crossed links 10 to be more readily compressed on screwing down the shell 7, so that the said crossed links will thereby be made to securely and firmly clasp the inserted bit 1 at a point immediately beyond the shoulder 2 thereon, as shown in Figs. 1 and 2.

In order to prevent the crossed links 10 from being pulled out of the brace-head, their spring arms or shanks 9 may be formed on or secured to a divided or split ring, such as 12, Fig. 4, or they may be integral with a divided spring-ring 13, Fig. 5, in which latter case the two crossed links, with their shanks and the divided ring portion or base, may be all constructed in one piece from a suitable length of steel wire. In either form of construction the divided base-ring 12 or 13 is sprung into an annular groove or recess 14, Figs. 1 and 2, formed in the inner end portion of the outside shell '7 of the brace-head] With the form of construction shown in Fig. 5 the crossed spring-links 10 can be readily inserted into the shell 7 from either end thereof. Obviously when the base-ring 12 or 13, as the case may be, is sprung into the annular groove or recess 14 of the shell 7 the crossed spring-links 10 will be thereby held in said shell in such manner that after the shell has been screwed onto the socket-piece 5 and the crossed links thus compressed onto the inserted bit the latter will not only be held firmly in its socket, but can be withdrawn directly from the work without turning the bit backward and with no liability of pulling out the bit from its socket nor of detaching the spring base-ring from its secure engagement in the outer shell of the brace-head.

Heretofore with brace-heads of ordinary construction the bit-fastenings were liable to spring or loosen when the tool was subjected to a hard test, such as reaming a hole in iron or to out a thread with screws, cutting-dies, or tools of like nature. My improved bracehead, on the other hand, will hold the bit firmly and securely, so that no matter what the strain may be it will do its work well, for there is no chance of the fastenings giving way. The polygonal socket into which the bit is inserted will prevent the bit from turning therein, while the compressible springlinks crossing each other at the bit-shoulder andclamping thereon will hold the bit firmly, so that it is impossible for it to get loose whilein operation or to pull out from the brace-head when withdrawing the bit from the work. The bit can be fastened in its socket by about three turns of the shell 7,

thus effecting a large saving of time in firmly adjusting the bit. YVhen screwing the shell onto the socket-piece, it turns readily over the spring-arms 9 of the crossed links, said arms 9' being retained meanwhile in the grooves 8 of said socket-piece, and bysufficiently tightening the shell onto the socketpiece the crossed links 10 are thereby compressed into firm clamping engagement with the bit at the shoulder 2 thereon, while at the same time the compressed cross-links will exert by their resiliencya locking action within the shell 7 to prevent it from working loose. By reason of its simple, effective, and durable construction the brace-head will stand extremely-hard usage without material injury.

\Vhat I claim as my invention is- 1. In a brace-head, the combination of a socket-piece to receive the shank of a bit, a shell movable on said socket-piece, and compressible crossed links held between said socket-piece and shell and adapted to be compressed by said shell into clamping engage.- nient with the bit to. hold the same firmly 'in its socket, substantially as described.

2. In a brace-head, the combination of an externally-screw-threaded socket-piece to receive the shank of a bit, an internally-screwthreaded shell to engage the said socketpiece,and spring clam ping-links held between said socket-piece and shell and provided with looped portions crossing each other in such manner as to be capable of securely embracing the inserted bit and be clamped thereon by screwing down said shell, whereby the bit will be held firmly in its socket, substantially as described.

3. In a brace-head, the combination of an externally screw threaded and longitudinally-grooved socket-piece having in one end a socket to receive the shank of a bit, an internally-screw-threaded shell to engage the said socket-piece, and crossed spring-links arranged in the grooves of said socket-piece and compressible by screwing down said shell, whereby the crossed portions of said links will be made to securely clamp the bit and hold it firmly in its socket, substantially as described.

4. In a brace-head, the combination of an externally screw threaded and longitudinally-grooved socket-piece having a socket to receive the shank of a bit, an internallyscrew-threaded shell to engage the said socketpiece and provided in one end with an annular groove or recess, and compressible crossed links comprising spring-arms arranged in they grooves of the socket-piece and a divided spring base-ring engaged in the annular groove or recess of the shell, the crossed portions of said links being adapted to clampthe bit by screwing down said shell, whereby the bit is held firmly in its socket, substantially as described.

IIO

5. In a brace-head, the combination of an eXternally-screw-threaded socket-piece having a socket to receive a bit and provided on two sides with parallel lon gitudinally-extended grooves, an internally-screw-threaded shell to engage the said socket-piece, and crossed spring-links provided with a base ring engaged in said shell and with arms or shanks engaged in the grooves of the socket- IO piece, the crossed portions of said links being adapted to be clamped onto the bit by screwing down said shell, to hold the bit firmly in its socket, substantially as described.

7 In testimony whereof I have hereunto set my hand in presence of two subscribing wit 15 

